The invention relates to a modular printing machine system for printing on sheets, including a first printing machine of satellite construction type having a central first impression cylinder and at least four printing devices assigned thereto and a sheet feeder, a second printing machine having a sheet feeder and a second impression cylinder, and a coupling device for coupling the printing machines to one another for in-line operation thereof.
Printing machine systems of this general type are described in U.S. Pat. No. 5,660,108 and published German Patent Documents DE 43 03 797 A1, DE 195 03 619 A1 and DE 197 43 770 A1. The system described in the last-mentioned German patent document includes a satellite printing-unit group as the first printing machine and an imprinting-unit group as the second printing machine. As FIG. 3 of this German patent document shows, a multiple-size impression cylinder of the imprinting-unit group is exactly the same size as an impression cylinder of four times the size in the satellite printing-unit group.
It is accordingly an object of the invention to provide a further improved modular printing machine system.
With the foregoing and other objects in view, there is provided, in accordance with the invention, a modular printing machine system for printing on sheets, including a first printing machine of satellite construction type having a central first impression cylinder and at least four printing devices assigned thereto and a sheet feeder, a second printing machine having a sheet delivery, and a coupling device for coupling the printing machines to one another for in-line operation thereof. A second impression cylinder is in the second printing machine. The second impression cylinder and the first impression cylinder are of different sizes.
In accordance with another feature of the invention, the first impression cylinder has a circumferential length exactly four times as great as the circumferential length of the second impression cylinder.
In accordance with a further feature of the invention, the second printing machine includes a single applicator cylinder disposed for applying one of ink and varnish, respectively, to sheets carried by the second impression cylinder.
In accordance with an added feature of the invention, the second printing machine includes a first form cylinder, a second form cylinder, and an applicator cylinder disposed for transferring one of ink and varnish, respectively, from the first and second form cylinders onto the sheets.
In accordance with an additional feature of the invention, the second printing machine includes at least one zoneless metering device for metering one of ink and varnish, respectively, and the metering device includes an assembly selected from the group consisting of a screen roller and a doctor blade engaged therewith, on the one hand, and a trough, a dip roller disposable in the trough, and a metering roller engageable with the dip roller, on the other hand.
In accordance with yet another feature of the invention, the modular printing machine system includes a feeding device disposed for transferring a sheet to the second impression cylinder, and at least one adjusting device assigned, for register correction, to the feeding device, the at least one adjusting device having a control link to at least one sensor assigned to the first impression cylinder for monitoring the position of a sheet carried by the first impression cylinder.
In accordance with yet a further feature of the invention, the modular printing machine system includes a non-impact printer for the in-line printing of the sheets, the non-impact printer being integrated in the printing machine system, and being an inkjet printer.
In accordance with yet an added feature of the invention, the modular printing machine system includes a transport device for transporting the sheets, the transport device being disposed between the first and the second impression cylinders, and being constructed as one of an electromagnetic linear drive and a transport belt, respectively.
In accordance with yet an additional feature of the invention, the transport device includes a suction device.
In accordance with another feature of the invention, for holding the sheet, the transport device includes at least one tongs-type gripper for lying on a side of the sheet which is to be printed, the gripper being less than 1.0 mm thick.
In accordance with a concomitant feature of the invention, the tongs-type gripper is less than 0.5 mm thick.
Thus, the printing machine system according to the invention is distinguished by the fact that the circumferential length of the first impression cylinder of the first printing machine and the circumferential length of the second impression cylinder of the second printing machine are different.
The second impression cylinder is preferably smaller than the first impression cylinder, the circumference of which is an integral multiple of the circumference of the second impression cylinder. This is particularly advantageous when the second impression cylinder has fewer than four applicator cylinders, such as two, for example, assigned thereto or when the second impression cylinder has only a single applicator cylinder assigned thereto. The fact that the size of the second impression cylinder is reduced by comparison with the first impression cylinder means that the second printing machine can be of very compact construction. The compact construction of the second printing machine, in turn, reduces the manufacturing costs thereof, and only a relatively small floor area is needed for the space-saving erection of the second printing machine.
This advantage is achieved by deviating, in accordance with the invention, from the established design, which is taught in all the published documents mentioned at the introduction hereto, according to which the impression cylinders of the two printing machines are supposed to be of the same size. As is shown in the aforementioned German Patent Document DE 197 43 770 A1, before the invention of the instant application, this design was adhered to even when fewer than four, such as two printing devices, for example, were assigned to the second impression cylinder of the second printing machine.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a modular printing machine system for printing on sheets, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.